Chapter 5-8 Biology Exam

Which two types of molecules make up most of the plasma membrane?

1. Phospholipids and proteins.

Describe how the hydrophobic tails and hydrophilic heads of phospholipids are arranged in a cell membrane.

Phospholipids are arranged with their hydrophobic tails facing the inner part of the membrane and hydrophilic heads facing the aqueous environments outside and inside the cell.

Which membrane proteins have attached carbohydrate chains that help cells recognize one another?

Glycoproteins

In this transport, a membrane pump coupled to ATP would be considered what type of transport?

Active transport/Primary active transport

In a saltwater solution, what term describes the substance that dissolves another substance? Being dissolved?

Solvent (dissolves another substance), solute (being dissolved).

What type of passive transport moves a substance down its concentration gradient with help from a membrane protein?

facilitated diffusion

Which substances cross the lipid bilayer most easily; small nonpolar gases (oxygen and carbon dioxide), sugars, large proteins, or ions?

Small, nonpolar gases such as oxygen (O₂) and carbon dioxide (CO₂) cross the lipid bilayer most easily, without any assistance

What moves during osmosis, and in which direction does it move across a selectively permeable membrane?

only the solvent molecules (usually water)

Which type of surrounding solution allows plant cells to take in water and develop turgor pressure?

A hypotonic surrounding solution

What process allows a white blood cell to surround and take in a bacterium?

phagocytosis

A snail loses water and shrinks after exposure to a salty solution. How would you classify the solution relative to the snail’s cells?

Hypertonic

What vesicle-mediated process releases insulin from a pancreatic cell into the fluid outside the cell?

Pancreatic β‑Cells

Describe a uniporter and explain how you would distinguish it from a symporter and an antiporter.

Uniporters, symporters, and antiporters are integral membrane proteins that facilitate the transport of molecules across cell membranes, differing primarily in the number of molecules they transport and the direction of transport.

Energy stored in the chemical bonds of sugar illustrate what type of energy?

The energy stored in the chemical bonds of sugar is called chemical energy, which is a form of potential energy.

The total entropy of the universe is always increasing, but inside the cells entropy is?

Locally Decreasing

Energy is released when what is broken in ATP?

hydrolysis of its terminal phosphate bond

How many phosphate groups are present in ADP and ATP?

ATP (adenosine triphosphate) has three phosphate groups, while ADP (adenosine diphosphate) has two phosphate groups.

What region of an enzyme binds the substrate?

The active site

Which suffix commonly appears at the end of an enzyme?

-ase

In a graph comparing catalyzed and uncatalyzed reactions, in the catalyzed reaction, what is being lowered?

Activation energy

What are coenzymes?

Coenzymes are small, non-protein organic molecules that assist enzymes in catalyzing biochemical reactions by transferring electrons, atoms, or functional groups.

In what form does NADH carry energy that can later support ATP production?

NADH carries energy in the form of high‑energy electrons (and a proton) stored in its reduced state, which are later used to generate a proton gradient that drives ATP synthesis

In this inhibition, a later product of a pathway acts earlier to prevent over accumulation of the final product?

end‑product inhibition

During sustained running with adequate oxygen delivery, which metabolic process supplies most ATP?

the aerobic (oxidative) metabolism of carbohydrates and fats via the citric acid cycle and oxidative phosphorylation supplies the majority of ATP

Which cells lack mitochondria?

Red blood cells (erythrocytes) and all prokaryotic cells (bacteria and archaea)

What are the folds of the inner mitochondrial membrane called?

cristae

When is carbon dioxide released in cellular respiration?

Carbon dioxide is released during pyruvate oxidation and the citric acid cycle in cellular respiration.

Which stage can proceed whether oxygen is available or absent?

Glycolysis

Compared with exhaled air, does inhaled air contain more or less oxygen and carbon dioxide?

Inhaled air contains more oxygen and less carbon dioxide than exhaled air

What two three-carbon molecules result when one glucose molecule completes glycolysis?

When one glucose molecule (a six‑carbon sugar) completes glycolysis, it is split into two molecules of pyruvate, each containing three carbon atoms

Which stage produces most ATP during aerobic cellular respiration?

Oxidative phosphorylation and chemiosmosis.

In which mitochondrial compartment does the citric acid cycle occur in eukaryotic cells?

the mitochondrial matrix — the inner fluid compartment of the mitochondria

When NADH and FADH2 donates electrons to the electron transport chain, are they oxidized or reduced? Explain using electron loss or gain.

When NADH and FADH₂ donate electrons to the electron transport chain (ETC), they are oxidized.

Reasoning in terms of electron loss/gain:

• Oxidation is defined as the loss of electrons (and often protons in biological systems).

• Reduction is the gain of electrons.

What product forms when oxygen accepts electrons and combines with hydrogen ions at the end of aerobic respiration?

Water

Where in a eukaryotic cell does glycolysis occur?

Cytosol

What is the original energy source that drives photosynthesis in plants?

Sunlight